Parts Presentation to Multi-Arm Assembly Robots

Abstract

Of the many methods of orienting and presenting parts to assembly machines, the vibratory bowl feeder is by far the most common device because of its large bulk storage capacity, high rate of parts feeding, compact structure and ability to deal with a wide variety of part shapes. Unfortunately bowl feeders are relatively expensive both in terms of equipment, tooling and changeover costs, especially when It is integrated in a multi-arm robotic assembly system where part utilisation is low and frequent equip rent changeovers are necessary due to the requirement to assemble different products. It can be shown that it is the disproportionately high cost of the feeding equipment, of whatever type, which makes robotic assembly systems difficult to justify economically and there is a need to reduce the costs associated with this equipment considerably. A linear vibratory feeder designed to present parts to robotic assembly equipment is currently being developed at the University of Salford. It is anticipated that the use of multiple linear feed tracks mounted on a common drive will not only reduce the capital cost of the equipment per track and the changeover costs but also that of the orienting device production since simple straight feed tracks will be produced on an NC machining centre using interactive computer-aided part programming. This paper describes the philosophy of the approach, the design, construction and testing of the basic feeder and the part programming methods for simple orienting systems.